What are keloids?
When a wound heals, it leaves a scar. A keloid (also called a keloid scar) is the name given to a scar that overgrows and becomes larger than the original wound. It is not uncommon for a scar to become slightly thick and raised. This is called a hypertrophic scar. Unlike hypertrophic scars, keloids:
- Can develop after very minor skin damage, such as an acne spot, or sometimes without any obvious trauma to the skin (spontaneous keloids).
- Spread beyond the original area of skin damage.
- May be permanent.
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What causes keloids?
This is not fully understood, but keloids happen when there is over production of collagen (the skin’s structural protein). Most people’s skin scars normally, and only a minority of people develop keloids. Keloids are not contagious. There are some risk factors that increase the likelihood of a person developing keloids.
- can affect anyone, but they are more common in people with dark skin (especially those of African, Hispanic or Chinese descent)
- are more common after skin injury on the upper chest, breastbone (sternum), shoulders, chin, neck, lower legs and earlobes (especially after ear piercing)
- are most likely to form following burns, acne scars and wounds that become infected or are under tension whilst healing
- may develop from surgical scars
- are more likely to affect people who have previously had a keloid if their skin is damaged again
- most commonly arise between puberty and 30 years of age
- may appear or enlarge during pregnancy
Are keloids hereditary?
Not usually, but the tendency to develop keloids can run in families. Studies have shown that 5-10% of Europeans with keloids have a positive family history (i.e. at least one other member of their family has keloids).
What are the symptoms of a keloid?
While keloids are growing, they may feel itchy, prickly and/or sore. Once they have stopped growing there is usually no discomfort. If they are located over or near a joint, they can restrict movement.
What does a keloid look like?
Keloids are enlarged, raised scars and can be pink, red, skin-coloured or darker than surrounding skin. They usually feel firm and smooth. They are shiny and hairless. A keloid can appear within 3-4 weeks of a skin wound but can take a year or longer to appear. It may continue to grow for months or years, enlarging beyond the edges of the original skin damage. Multiple keloids may develop, especially after acne or chickenpox, although most people only have one or two.
How will it be diagnosed?
The doctor will usually make the diagnosis of a keloid just by looking at the skin so no tests are needed. If the diagnosis is uncertain, a skin biopsy (a procedure in which a sample of skin tissue from one of the patches is removed under local anaesthetic, processed, and examined under a microscope) can be taken under local anaesthetic.
Can a keloid be removed?
Surgically removing/ excising or “cutting out” a keloid is rarely a success as this causes a larger wound and the keloids is likely to regrow in it. If it is excised the risk of regrowth may be reduced by compression dressings or steroid injections following the procedure (see below).
How can a keloid be treated?
Unfortunately, there is no cure for keloids. Treatment can sometimes help to flatten them and reduce irritation. There is currently no evidence that any single form of treatment is better than another and keloids often regrow in the same place. Treatment options include:
What can I do?
People with risk factors (outlined above) for getting keloids are advised to avoid skin trauma such as tattooing, body piercing and unnecessary surgical procedures / cosmetic skin surgery, particularly on high-risk areas such as the chest or earlobes. In the case of acne, prompt and effective medical therapy is important to limit the risk of scarring.
This information is provided by the British Association of Dermatologists.
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